A case of West syndrome with atypical massive gray matter heterotopia that is well controlled by ACTH therapy

A 4 month old female infant with atypical asymmetrical massive gray matter heterotopia diagnosed as West syndrome is described. Her seizure initially appeared as afebrile general tonic and clonic convulsion and progressed to typical West syndrome consisting of clusters of myoclonic spasms of the extremities, mainly on the left side, accompanied by head and eye deviation to the right side. Electroencephalogram (EEG) presented typical hypsarrhythmia and cranial computerized tomography (CT) and magnetic resonance imaging (MRI) showed massive heterotopic gray matter in the right hemisphere with the same density or intensity as cortical gray matter. Single photon emission computed tomography (SPECT), using N-isopropyl-p-¹²³I-iodoamphetamine (¹²³I-IMP), demonstrated decreased blood flow in the ectopic lesion. Although clinical response to several anti-epileptic drugs was poor, her seizures were well controlled by relatively low dose adrenocorticotropic hormone (ACTH) therapy of 0.015 mg/kg per day followed by a combination of valproic acid and clonazepam.